samples/thread/test.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        test.cpp
   3 // Purpose:     wxWindows thread sample
   4 // Author:      Julian Smart(minimal)/Guilhem Lavaux(thread test)
   5 // Modified by:
   6 // Created:     06/16/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart, Markus Holzem, Guilhem Lavaux
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 /*
  13     TODO: use worker threads to update progress controls instead of writing
  14           messages - it will be more visual
  15  */
  16
  17 #ifdef __GNUG__
  18     #pragma implementation "test.cpp"
  19     #pragma interface "test.cpp"
  20 #endif
  21
  22 // For compilers that support precompilation, includes "wx/wx.h".
  23 #include "wx/wxprec.h"
  24
  25 #ifdef __BORLANDC__
  26     #pragma hdrstop
  27 #endif
  28
  29 #ifndef WX_PRECOMP
  30     #include "wx/wx.h"
  31 #endif
  32
  33 #if !wxUSE_THREADS
  34     #error "This sample requires thread support!"
  35 #endif // wxUSE_THREADS
  36
  37 #include "wx/thread.h"
  38 #include "wx/dynarray.h"
  39 #include "wx/time.h"
  40
  41 class MyThread;
  42 WX_DEFINE_ARRAY(wxThread *, wxArrayThread);
  43
  44 // Define a new application type
  45 class MyApp : public wxApp
  46 {
  47 public:
  48     virtual bool OnInit();
  49
  50 public:
  51     // all the threads currently alive - as soon as the thread terminates, it's
  52     // removed from the array
  53     wxArrayThread m_threads;
  54
  55     // crit section protects access to all of the arrays below
  56     wxCriticalSection m_critsect;
  57 };
  58
  59 // Create a new application object
  60 IMPLEMENT_APP(MyApp)
  61
  62 // Define a new frame type
  63 class MyFrame: public wxFrame
  64 {
  65 public:
  66     // ctor
  67     MyFrame(wxFrame *frame, const wxString& title, int x, int y, int w, int h);
  68
  69     // operations
  70     void WriteText(const wxString& text) { m_txtctrl->WriteText(text); }
  71
  72     // callbacks
  73     void OnQuit(wxCommandEvent& event);
  74     void OnAbout(wxCommandEvent& event);
  75     void OnClear(wxCommandEvent& event);
  76
  77     void OnStartThread(wxCommandEvent& event);
  78     void OnStartThreads(wxCommandEvent& event);
  79     void OnStopThread(wxCommandEvent& event);
  80     void OnPauseThread(wxCommandEvent& event);
  81     void OnResumeThread(wxCommandEvent& event);
  82
  83     void OnIdle(wxIdleEvent &event);
  84
  85 private:
  86     // helper function - creates a new thread (but doesn't run it)
  87     MyThread *CreateThread();
  88
  89     // just some place to put our messages in
  90     wxTextCtrl *m_txtctrl;
  91
  92     // remember the number of running threads and total number of threads
  93     size_t m_nRunning, m_nCount;
  94
  95     DECLARE_EVENT_TABLE()
  96 };
  97
  98 class MyThread : public wxThread
  99 {
 100 public:
 101     MyThread(MyFrame *frame);
 102
 103     // thread execution starts here
 104     virtual void *Entry();
 105
 106     // called when the thread exits - whether it terminates normally or is
 107     // stopped with Delete() (but not when it is Kill()ed!)
 108     virtual void OnExit();
 109
 110     // write something to the text control
 111     void WriteText(const wxString& text);
 112
 113 public:
 114     size_t   m_count;
 115     MyFrame *m_frame;
 116 };
 117
 118 MyThread::MyThread(MyFrame *frame)
 119         : wxThread()
 120 {
 121     m_count = 0;
 122     m_frame = frame;
 123 }
 124
 125 void MyThread::WriteText(const wxString& text)
 126 {
 127     wxString msg;
 128
 129     // before doing any GUI calls we must ensure that this thread is the only
 130     // one doing it!
 131
 132     wxMutexGuiEnter();
 133
 134     msg << text;
 135
 136     m_frame->WriteText(msg);
 137
 138     wxMutexGuiLeave();
 139 }
 140
 141 void MyThread::OnExit()
 142 {
 143     wxCriticalSectionLocker locker(wxGetApp().m_critsect);
 144
 145     wxGetApp().m_threads.Remove(this);
 146 }
 147
 148 void *MyThread::Entry()
 149 {
 150     wxString text;
 151
 152     text.Printf("Thread 0x%x started (priority = %d).\n",
 153                 GetID(), GetPriority());
 154     WriteText(text);
 155
 156     for ( m_count = 0; m_count < 10; m_count++ )
 157     {
 158         // check if we were asked to exit
 159         if ( TestDestroy() )
 160             break;
 161
 162         text.Printf("[%u] Thread 0x%x here.\n", m_count, GetID());
 163         WriteText(text);
 164
 165         // wxSleep() can't be called from non-GUI thread!
 166         wxThread::Sleep(1000);
 167     }
 168
 169     text.Printf("Thread 0x%x finished.\n", GetID());
 170     WriteText(text);
 171
 172     return NULL;
 173 }
 174
 175 // ID for the menu commands
 176 enum
 177 {
 178     TEST_QUIT          = 1,
 179     TEST_TEXT          = 101,
 180     TEST_ABOUT,
 181     TEST_CLEAR,
 182     TEST_START_THREAD  = 201,
 183     TEST_START_THREADS,
 184     TEST_STOP_THREAD,
 185     TEST_PAUSE_THREAD,
 186     TEST_RESUME_THREAD
 187 };
 188
 189 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 190     EVT_MENU(TEST_QUIT, MyFrame::OnQuit)
 191     EVT_MENU(TEST_ABOUT, MyFrame::OnAbout)
 192     EVT_MENU(TEST_CLEAR, MyFrame::OnClear)
 193     EVT_MENU(TEST_START_THREAD, MyFrame::OnStartThread)
 194     EVT_MENU(TEST_START_THREADS, MyFrame::OnStartThreads)
 195     EVT_MENU(TEST_STOP_THREAD, MyFrame::OnStopThread)
 196     EVT_MENU(TEST_PAUSE_THREAD, MyFrame::OnPauseThread)
 197     EVT_MENU(TEST_RESUME_THREAD, MyFrame::OnResumeThread)
 198
 199     EVT_IDLE(MyFrame::OnIdle)
 200 END_EVENT_TABLE()
 201
 202 // `Main program' equivalent, creating windows and returning main app frame
 203 bool MyApp::OnInit()
 204 {
 205     // Create the main frame window
 206     MyFrame *frame = new MyFrame((wxFrame *)NULL, "wxWindows threads sample",
 207                                  50, 50, 450, 340);
 208
 209     // Make a menubar
 210     wxMenu *file_menu = new wxMenu;
 211
 212     file_menu->Append(TEST_CLEAR, "&Clear log\tCtrl-L");
 213     file_menu->AppendSeparator();
 214     file_menu->Append(TEST_ABOUT, "&About");
 215     file_menu->AppendSeparator();
 216     file_menu->Append(TEST_QUIT, "E&xit\tAlt-X");
 217     wxMenuBar *menu_bar = new wxMenuBar;
 218     menu_bar->Append(file_menu, "&File");
 219
 220     wxMenu *thread_menu = new wxMenu;
 221     thread_menu->Append(TEST_START_THREAD, "&Start a new thread\tCtrl-N");
 222     thread_menu->Append(TEST_START_THREADS, "Start &many threads at once");
 223     thread_menu->Append(TEST_STOP_THREAD, "S&top a running thread\tCtrl-S");
 224     thread_menu->AppendSeparator();
 225     thread_menu->Append(TEST_PAUSE_THREAD, "&Pause a running thread\tCtrl-P");
 226     thread_menu->Append(TEST_RESUME_THREAD, "&Resume suspended thread\tCtrl-R");
 227     menu_bar->Append(thread_menu, "&Thread");
 228     frame->SetMenuBar(menu_bar);
 229
 230     // Show the frame
 231     frame->Show(TRUE);
 232
 233     SetTopWindow(frame);
 234
 235     return TRUE;
 236 }
 237
 238 // My frame constructor
 239 MyFrame::MyFrame(wxFrame *frame, const wxString& title,
 240                  int x, int y, int w, int h)
 241        : wxFrame(frame, -1, title, wxPoint(x, y), wxSize(w, h))
 242 {
 243     m_nRunning = m_nCount = 0;
 244
 245     CreateStatusBar(2);
 246
 247     m_txtctrl = new wxTextCtrl(this, -1, "", wxPoint(0, 0), wxSize(0, 0),
 248                                wxTE_MULTILINE | wxTE_READONLY);
 249
 250 }
 251
 252 MyThread *MyFrame::CreateThread()
 253 {
 254     MyThread *thread = new MyThread(this);
 255
 256     if ( thread->Create() != wxTHREAD_NO_ERROR )
 257     {
 258         wxLogError("Can't create thread!");
 259     }
 260
 261     wxCriticalSectionLocker enter(wxGetApp().m_critsect);
 262     wxGetApp().m_threads.Add(thread);
 263
 264     return thread;
 265 }
 266
 267 void MyFrame::OnStartThreads(wxCommandEvent& WXUNUSED(event) )
 268 {
 269     static wxString s_str;
 270     s_str = wxGetTextFromUser("How many threads to start: ",
 271                               "wxThread sample",
 272                               s_str, this);
 273     if ( s_str.IsEmpty() )
 274         return;
 275
 276     size_t count, n;
 277     sscanf(s_str, "%u", &count);
 278     if ( count == 0 )
 279         return;
 280
 281     wxArrayThread threads;
 282
 283     // first create them all...
 284     for ( n = 0; n < count; n++ )
 285     {
 286         wxThread *thr = CreateThread();
 287
 288         // we want to show the effect of SetPriority(): the first thread will
 289         // have the lowest priority, the second - the highest, all the rest
 290         // the normal one
 291         if ( n == 0 )
 292             thr->SetPriority(WXTHREAD_MIN_PRIORITY);
 293         else if ( n == 1 )
 294             thr->SetPriority(WXTHREAD_MAX_PRIORITY);
 295         else
 296             thr->SetPriority(WXTHREAD_DEFAULT_PRIORITY);
 297
 298         threads.Add(thr);
 299     }
 300
 301     wxString msg;
 302     msg.Printf("%d new threads created.", count);
 303     SetStatusText(msg, 1);
 304
 305     // ...and then start them
 306     for ( n = 0; n < count; n++ )
 307     {
 308         threads[n]->Run();
 309     }
 310 }
 311
 312 void MyFrame::OnStartThread(wxCommandEvent& WXUNUSED(event) )
 313 {
 314     MyThread *thread = CreateThread();
 315
 316     if ( thread->Run() != wxTHREAD_NO_ERROR )
 317     {
 318         wxLogError("Can't start thread!");
 319     }
 320
 321     SetStatusText("New thread started.", 1);
 322 }
 323
 324 void MyFrame::OnStopThread(wxCommandEvent& WXUNUSED(event) )
 325 {
 326     // stop the last thread
 327     if ( wxGetApp().m_threads.IsEmpty() )
 328     {
 329         wxLogError("No thread to stop!");
 330     }
 331     else
 332     {
 333         wxGetApp().m_critsect.Enter();
 334
 335         wxThread *thread = wxGetApp().m_threads.Last();
 336
 337         // it's important to leave critical section before calling Delete()
 338         // because delete will (implicitly) call OnExit() which also tries
 339         // to enter the same crit section - would dead lock.
 340         wxGetApp().m_critsect.Leave();
 341
 342         thread->Delete();
 343
 344         SetStatusText("Thread stopped.", 1);
 345     }
 346 }
 347
 348 void MyFrame::OnResumeThread(wxCommandEvent& WXUNUSED(event) )
 349 {
 350     wxCriticalSectionLocker enter(wxGetApp().m_critsect);
 351
 352     // resume first suspended thread
 353     size_t n = 0, count = wxGetApp().m_threads.Count();
 354     while ( n < count && !wxGetApp().m_threads[n]->IsPaused() )
 355         n++;
 356
 357     if ( n == count )
 358     {
 359         wxLogError("No thread to resume!");
 360     }
 361     else
 362     {
 363         wxGetApp().m_threads[n]->Resume();
 364
 365         SetStatusText("Thread resumed.", 1);
 366     }
 367 }
 368
 369 void MyFrame::OnPauseThread(wxCommandEvent& WXUNUSED(event) )
 370 {
 371     wxCriticalSectionLocker enter(wxGetApp().m_critsect);
 372
 373     // pause last running thread
 374     int n = wxGetApp().m_threads.Count() - 1;
 375     while ( n >= 0 && !wxGetApp().m_threads[n]->IsRunning() )
 376         n--;
 377
 378     if ( n < 0 )
 379     {
 380         wxLogError("No thread to pause!");
 381     }
 382     else
 383     {
 384         wxGetApp().m_threads[n]->Pause();
 385
 386         SetStatusText("Thread paused.", 1);
 387     }
 388 }
 389
 390 // set the frame title indicating the current number of threads
 391 void MyFrame::OnIdle(wxIdleEvent &event)
 392 {
 393     // update the counts of running/total threads
 394     size_t nRunning = 0,
 395            nCount = wxGetApp().m_threads.Count();
 396     for ( size_t n = 0; n < nCount; n++ )
 397     {
 398         if ( wxGetApp().m_threads[n]->IsRunning() )
 399             nRunning++;
 400     }
 401
 402     if ( nCount != m_nCount || nRunning != m_nRunning )
 403     {
 404         m_nRunning = nRunning;
 405         m_nCount = nCount;
 406
 407         wxLogStatus(this, "%u threads total, %u running.", nCount, nRunning);
 408     }
 409     //else: avoid flicker - don't print anything
 410 }
 411
 412 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event) )
 413 {
 414     size_t count = wxGetApp().m_threads.Count();
 415     for ( size_t i = 0; i < count; i++ )
 416     {
 417         wxGetApp().m_threads[0]->Delete();
 418     }
 419
 420     Close(TRUE);
 421 }
 422
 423 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event) )
 424 {
 425     wxMessageDialog dialog(this, "wxWindows multithreaded application sample\n"
 426                                  "(c) 1998 Julian Smart, Guilhem Lavaux\n"
 427                                  "(c) 1999 Vadim Zeitlin",
 428                            "About wxThread sample",
 429                            wxOK | wxICON_INFORMATION);
 430
 431     dialog.ShowModal();
 432 }
 433
 434 void MyFrame::OnClear(wxCommandEvent& WXUNUSED(event))
 435 {
 436     m_txtctrl->Clear();
 437 }